1. Field of the Invention
The present invention relates to a switching mechanism for switching over the photographing mode of a camera from a shutter speed priority photographing mode or programmed photographing mode (hereinafter this group of modes are referred to generally as diaphragm control mode) to a diaphragm priority photographing mode or a manual photographing mode (hereinafter this group of modes are referred to generally as non-diaphragm control mode) and vice versa.
2. Description of the Prior Art
In the known switching mechanism of the type mentioned above, setting of the camera to the non-diaphragm control mode is effected by bringing a photographing mode switching-over member to its non-diaphragm control mode setting position. The switchover member is allowed to move toward another position, its diaphragm control mode setting position, only when the present diaphragm ring is in a position for the minimum aperture. By moving the switchover member to the diaphragm control mode setting position, setting of the camera to the diaphragm control mode is effected. Herein, for the purpose of this specification, the term "a position for the minimum aperture" means such position in which the diaphragm ring sets the smallest opening. As well known in the art, when it is desired to effect photographing in diaphragm control mode, the diaphragm ring must be brought into the position for the minimum aperture without failure. In this respect, the above described known switching mechanism has the advantage that the operator can not forget to set the diaphragm ring to the position for the minimum aperture when he wishes to carry out photographing in the diaphragm control mode. However, the known mechanism involves a disadvantage. That is, since the diaphragm ring is locked by selecting the diaphragm control mode, no change-over from the diaphragm control mode to non-diaphragm control mode is allowed unless the diaphragm ring is again unlocked, which requires that the switchover member be brought into the nondiaphragm control mode position. Therefore, in order to effect photographing in the non-diaphragm control mode, the operator has to operate the switchover member and the diaphragm ring separately. This makes the operation of camera complicated and troublesome for the operator.